Pardon the mess please!
The rig: active biamp of the big heils with fostex FF225k in "Rethm the second" cabinets, first order at 4600. SET on the heils, UCD on the fostex. For those uninitiated with the Rethms, they're sort of a hybrid horn/acoustic labyrinth designed for use with lowthers.
Questions? Comments? Moans and Groans? I'm working on some neat stands for the heils to match the rethms. It's pretty neutral and transparent though 🙂
The rig: active biamp of the big heils with fostex FF225k in "Rethm the second" cabinets, first order at 4600. SET on the heils, UCD on the fostex. For those uninitiated with the Rethms, they're sort of a hybrid horn/acoustic labyrinth designed for use with lowthers.
Questions? Comments? Moans and Groans? I'm working on some neat stands for the heils to match the rethms. It's pretty neutral and transparent though 🙂
New stands to match the rethms
Tall stands, details and pic at
Stands on a blog!
Oak, PVC, expanding urethane, and ply with heils on top! Sounds great, XO has been moved up to 6500Hz, still first order active. The heils and these fostex have very similar dispersion characteristics even that high, which is a major shortcoming in many midwoof+tweet designs.
Tall stands, details and pic at
Stands on a blog!
Oak, PVC, expanding urethane, and ply with heils on top! Sounds great, XO has been moved up to 6500Hz, still first order active. The heils and these fostex have very similar dispersion characteristics even that high, which is a major shortcoming in many midwoof+tweet designs.
I like that alot.........
That system is nice ......I like the way it is set up. I am in that sort of land also. I see some seroiuse good sonics happening there. I am intrested in the Heils's I use the Fountek neocd3 now, to get a taste.. a fast 4" Coral & active bottom @ 140 . please give some insight to how it perform sonically. I could care less about any measurements.....
That system is nice ......I like the way it is set up. I am in that sort of land also. I see some seroiuse good sonics happening there. I am intrested in the Heils's I use the Fountek neocd3 now, to get a taste.. a fast 4" Coral & active bottom @ 140 . please give some insight to how it perform sonically. I could care less about any measurements.....
Would they be to high when mounted on top of the Rethms?
It would help against reflections and improve point-source behavior...
It would help against reflections and improve point-source behavior...
v-bro: On the link from the second post, you can see some taller stands I did to reduce reflections. Yes, I know top mounting would be an improvement in point-source behavior, and am considering it, however I'm concerned about getting the mounting stable enough, I sure don't need the heils falling off the speaker onto my kid's head, those suckers are heavy!
JandG, well, sonically, they're pretty good, though I am still fiddling with the crossover and some other items (just revised my preamp last night too). Very transparent, but I don't know that the fostex are keeping up with the heils that high up, there seems some detail lost.
I'll keep this thread updated as it progresses, certainly it's a unique sort of setup.
JandG, well, sonically, they're pretty good, though I am still fiddling with the crossover and some other items (just revised my preamp last night too). Very transparent, but I don't know that the fostex are keeping up with the heils that high up, there seems some detail lost.
I'll keep this thread updated as it progresses, certainly it's a unique sort of setup.
Sometimes it just takes.....
Sometimes it just takes someone pointing out what you already knew...
improvements galore, as you might expect.
Sometimes it just takes someone pointing out what you already knew...
improvements galore, as you might expect.
Yeah, there's some good improvements in terms of perceived detail and transient speed. The fostex isn't a plodding clumsy beast by any means, having a very very low Qts and super motor. Nice setup, where are you crossing the quads over?
About 200-250 hz. Use a DIY-ed version of Marchand xm-46 at the moment, lovely simple technique and easy to tweak and not expensive way of filtering....😉
Hehehe, the marchand circuits are very effective. I use the XM-126 (the tube one with outboard PSU), and I love the ability to swap the filter boards out and control both frequency AND slope, most analog crossovers only let you control frequency.
Nice one, but I made several pre-made filters in different slopes and frequencies. By this experimenting I now know exactly how to tune a "tailor-made" circuit.
The marchand xm-46-type filter I use doesn't need a supply, it's passive:
http://www.marchandelec.com/ftp/xm46man.pdf
That's why I want to add a buffer stage like this:
http://www.autocostruire.com/catalo...d=304&osCsid=e074110ffca3d290557082838e0019ee
😎 😎 😎
The marchand xm-46-type filter I use doesn't need a supply, it's passive:
http://www.marchandelec.com/ftp/xm46man.pdf
That's why I want to add a buffer stage like this:
http://www.autocostruire.com/catalo...d=304&osCsid=e074110ffca3d290557082838e0019ee
😎 😎 😎
v-bro said:
Where did you get your chokes? Or did you make them? More than once i've done a bit of research on diying similar but get stumped by the chokes.
dave
I built them myself, by using an LCR-meter (really AM glad to have one...).
I'm testing a few different ones I made at the moment, with different core's...
I'm testing a few different ones I made at the moment, with different core's...
On subject:
I know how muc potential this kind of combo can have... chris has the bipolar Fostex FW227/Heils set up at the moment.
What is the story on the Rythems? I'd love to see some detail pictures (insides too)
dave
I know how muc potential this kind of combo can have... chris has the bipolar Fostex FW227/Heils set up at the moment.
What is the story on the Rythems? I'd love to see some detail pictures (insides too)
dave
I'll take a few more exterior pictures, but the interior may not really be appropo. The Rethms are a commercial product, they sell just the cabinets sometimes (some dealers put other fullrangers in besides the lowther). A fortuitous set of circumstances brought this (and another) pair of cabs into my posession.
Their construction is a hybrid horn/acoustic labyrinth. There's a large plastic piece that mounts onto the back of the magnet (looks somewhat like a giant tapered phallus) that gives it an expanding 'ring shaped' cross section, which is in many ways something like a conical horn. This somewhat damps larger cone excursion and prevents backwave reflections from hitting the diaphragm. After this, it's a textbook acoustic labyrinth, from what I know, IE, an unstuffed TL.
There are 2 circular openings/terminii of different diameter on the sides, which vent both ways (left and right), I'm not sure if there's an increase in final taper before these (another horn-like element).
The Fostex drivers are ones I found to be the best compromise for me, as I am not fond of the lowther top end. These FF225ks are very smooth in terms of response, and have an incredibly powerful motor, and seem well-damped in general. Pretty impressive dispersion for a non-whizzer 8, too. The sacrifice is, 14k is the ABSOLUTE limit of their top end, beyond that, it's an extremely steep rolloff. I prefer wideband mids to true 'fullrangers', as a general rule, taking the frequency extension over the 'ultimate' in coherence.
I'll post some more pics as time goes on, I'm going to try to keep the blog pretty well updated, Baddy's Blog
but will post here when I have some more pics of different angles.
Their construction is a hybrid horn/acoustic labyrinth. There's a large plastic piece that mounts onto the back of the magnet (looks somewhat like a giant tapered phallus) that gives it an expanding 'ring shaped' cross section, which is in many ways something like a conical horn. This somewhat damps larger cone excursion and prevents backwave reflections from hitting the diaphragm. After this, it's a textbook acoustic labyrinth, from what I know, IE, an unstuffed TL.
There are 2 circular openings/terminii of different diameter on the sides, which vent both ways (left and right), I'm not sure if there's an increase in final taper before these (another horn-like element).
The Fostex drivers are ones I found to be the best compromise for me, as I am not fond of the lowther top end. These FF225ks are very smooth in terms of response, and have an incredibly powerful motor, and seem well-damped in general. Pretty impressive dispersion for a non-whizzer 8, too. The sacrifice is, 14k is the ABSOLUTE limit of their top end, beyond that, it's an extremely steep rolloff. I prefer wideband mids to true 'fullrangers', as a general rule, taking the frequency extension over the 'ultimate' in coherence.
I'll post some more pics as time goes on, I'm going to try to keep the blog pretty well updated, Baddy's Blog
but will post here when I have some more pics of different angles.
I will make some pictures of the coils, but have to borrow a camera from a friend...can take some time...
I used wire from an old but unused transformer and wound it on a small ferrite core from a tannoy speaker filter, in my place you literally trip on the filterboards laying around. So sourcing some ferrite core is no problem I guess, still wonder if I can better use air-cores?
My guess is that ferrite based cores are better in this field...
Still experimenting though, have to borrow a friend to do some A-B testing..😱
To Planet 10:
Is there some problem I don't know of that you can tell me about on making chokes? 😕
I used wire from an old but unused transformer and wound it on a small ferrite core from a tannoy speaker filter, in my place you literally trip on the filterboards laying around. So sourcing some ferrite core is no problem I guess, still wonder if I can better use air-cores?
My guess is that ferrite based cores are better in this field...
Still experimenting though, have to borrow a friend to do some A-B testing..😱
To Planet 10:
Is there some problem I don't know of that you can tell me about on making chokes? 😕
here's a picture of the chokes, one is with ferricore and halves of a piece of steel tube. The other is a ferrocore carrier with a plastic carrier inside, I removed the original wire with wire from a transformer. The ends of the wire is soldered to a thicker coated copperwire to give it more strength.
These are for a lowpass filter at aprox. 200 hz, the one I previously made I already sold....
But maybe I'm just lucky with all my old stock...I'm quite a collector, and everybody knows, I get a lot of old stuff from them....
I'm still not sure what makes the better coil, I can only make sure the measured value is allright, the rest is still unexplored territory for me...
These are for a lowpass filter at aprox. 200 hz, the one I previously made I already sold....
But maybe I'm just lucky with all my old stock...I'm quite a collector, and everybody knows, I get a lot of old stuff from them....
I'm still not sure what makes the better coil, I can only make sure the measured value is allright, the rest is still unexplored territory for me...
Attachments
ehm... pardon me, but the one with the steel halves is ferrocore and the other ferri(te)core....
I just looked it up..
I just looked it up..
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